PATIENTS who have previous ocular trauma often present with deficiencies that can include aniridia, aphakia, and corneal irregularity. Practitioners need to consider specialty lens options when deciding on a corrective design.
A 68-year-old patient reported for specialty lens fitting of her left eye secondary to globe rupture sustained from trauma during a fall. Surgical repair resulted in aniridia and aphakia (Figure 1). She was prescribed timolol b.i.d. OS to manage secondary glaucoma and is closely followed by a retina specialist.
Manifest refraction OS measured +12.50DS with a visual acuity (VA) of 20/400. Slit lamp examination revealed redundant conjunctiva and bleb formation, corneal striae, and scarring. Corneal topography showed corneal irregularity. A diagnostic intralimbal GP lens with a base curve (BC) of 8.1mm and –1.00DS power, accompanied by a +11.50DS over-refraction, improved her VA to 20/50.
LENS OPTIONS
Contact lens options were discussed including standard scleral, prosthetic scleral, and soft prosthetic lenses. A 16.5mm free-form scleral lens was designed based on corneoscleral topography and dispensed with +6.00DS, resulting in a VA of 20/40.
The patient reported not being able to see well, despite the improved VA, and complained of light sensitivity. She was having difficulty with lens application and midday fogging. She asked to try a soft lens to correct just her aphakia. A made-to-order silicone hydrogel soft lens with a BC of 8.6mm and +15.00DS power fit well on her eye; however, her best-corrected VA was limited to 20/400. This was not a surprise, based upon her manifest refraction.
A prosthetic soft contact lens was recommended as the next best option, manufactured with an iris print utilizing a small aperture that would not only reduce her light sensitivity but also provide a pinhole effect to improve her vision. A prosthetic scleral lens was ruled out based upon expense and her history with application issues.
A diagnostic 15mm soft lens with +15.00DS power and a generic prosthetic matrix with a 2mm pupil successfully fit her eye, and an over-refraction of +0.50D power provided her with a VA of 20/70. A color match of her right eye was made, and the final lens was ordered and dispensed (Figure 2). The patient was satisfied with the improved vision, reduced glare/light sensitivity, and comfort.
At follow-up, her VA had dropped to 20/200. Examination and optical coherence tomography imaging and referral back to her retina specialist confirmed that she had developed a macular hole, which is now being actively managed.
DISCUSSION
The simultaneous management of aphakia, aniridia, and corneal irregularity is challenging due to limited lens design options, cost, potential oxygen transmissibility issues, light sensitivity, and cosmetic concerns. For this patient, a prosthetic soft lens with a small pupil aperture that provided a pinhole effect improved her VA and reduced light sensitivity.
The pinhole mitigates higher-order aberrations and increases depth of focus (Applegate et al, 2003). An aperture smaller than 2mm can be considered, but risks include increased diffraction and reduced illumination (Labib, 2020). As this case highlights, practitioners need to be mindful of non-contact lens-related issues that may reduce vision, even after successful fitting.
REFERENCES
1. Applegate RA, Marsack JD, Ramos R, Sarver EJ. Interaction between aberrations to improve or reduce visual performance. J Cataract Refract Surg. 2003 Aug;29:1487-1495.
2. Labib BA. A Peek at the Pinhole. Rev Optom. 2020 Mar 15. Available at reviewofoptometry.com/article/a-peek-at-the-pinhole. Accessed 2024 June 11.
